Did our solar system form in bubbles around massive star?

Dec 26, 2017 (5 months ago)

IANS

New York, Dec 26 : Floating a new theory about the birth of our solar system, a new study says that it could have formed in the bubbles produced by a giant, long-dead star which was more than 40 to 50 times the size of our own Sun.

Despite the many impressive discoveries humans have made about the universe, scientists are yet to come to a consensus about the birth story of our solar system.

The general prevailing theory is that our solar system formed billions of years ago near a supernova.

But the new scenario, detailed in the Astrophysical Journal, instead begins with a giant type of star called a Wolf-Rayet star.

They burn the hottest of all stars, producing tonnes of elements which are flung off the surface in an intense stellar wind.

As the Wolf-Rayet star sheds its mass, the stellar wind plows through the material that was around it, forming a bubble structure with a dense shell.

"The shell of such a bubble is a good place to produce stars," because dust and gas become trapped inside where they can condense into stars, said study co-author Nicolas Dauphas, Professor at University of Chicago in the US.

The researchers estimate that one to 16 per cent of all Sun-like stars could be formed in such stellar nurseries.

The study addresses a nagging cosmic mystery about the abundance of two elements in our solar system compared to the rest of the galaxy.

Meteorites left over from the early solar system suggests there was a lot of aluminium-26.

In addition, studies increasingly suggest we had less of the isotope iron-60.

This brings scientists up short, because supernovae produce both isotopes.

"It begs the question of why one was injected into the solar system and the other was not," said co-author Vikram Dwarkadas from University of Chicago.

This brought the scientists to Wolf-Rayet stars, which release lots of aluminium-26, but no iron-60.

As for the fate of the giant Wolf-Rayet star, the researchers believe that its life ended long ago, likely in a supernova explosion or a direct collapse to a black hole.